Fluid catalytic hydroreforming with carbonized catalyst



Jan. 1, 1957 v. J. ANHORN ETAL 2,776,247

FLUID CATALYTIC HYDROREF'ORMING WITH CARBONIZED CATALYST Filed Sept. 24, 195] QNQUMQQRSNNN United States Patent Office FLUID CATALYTIC HYDROREFORMING WITH CARBONIZED CATALYST Victor J. Anhorn, Oakmont, Meredith M. Stewart, Penn Township, Allegheny County, and Wallace E. Morrow, Allison Park, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware Application September 24, 1951, Serial No. 247,976 6 Claims. (Cl. 1796-50) This invention relates to catalytic reforming in the presence of hydrogen and is more particularly concerned with certain improvements in the process when carried out in the presence of nely divided fluidized catalysts.

The terms catalytic reforming in the presence of hydrogen and hydroreforming wherever used in the specification and claims shall be understood to have their conventional meaning; that is, they shall be understood to mean a process in which hydrocarbon oils consisting essentially or predominantly of hydrocarbons boiling in the gasoline or naphtha range are subjected to treatment at a temperature in excess of 500 lF. in the presence of catalysts and in the presence of substantial quantities of added or recirculated hydrogen to produce a dehydrogenated or otherwise chemically reconstructed product, for example, of antiknock characteristics superior to those of the `starting material, with or without an accompanying change in molecularweight.

Previously suggested processes for catalytic reforming in the presence of hydrogen have had the disadvantage of requiring frequent regeneration of the catalyst as the result of inactivation of the catalyst by carbonaceous deposits. Also such processes in increasing the octane number of the charge have resulted in low liquid recovery due to excessive gasification o-f the charge stock. The present invention is based upon the discovery that by operating with a high carbon level on the tluidized catalyst, long reaction periods, such as periods of 100 hours or more, can be obtained and high octane gasoline is produced in high yields.

The process of the invention in general comprises the catalytic reforming of a hydrocarbon oil consisting of naphtha or a mixture of a predominant amount of naphtha and a minor amount of gas oil in the presence of hydrogen by -continuously contacting the naphtha or mix ture of naphtha and gas oil with hydrogen under hydro- D reforming conditions in the presence of a uidized finely divided hydroreforming catalyst containing through-out said process between about 10 and 25 percent of carbon by weight of the carbon-free catalyst. In a preferred embodiment the hydroreforming conditions comprise: a temperature between about 925 and 975 F., a pressure between about 200 and 1000 pounds per square inch gauge, a space velocity between about 0.5 and 5 weights of oil per weight of catalyst per hour, and a hydrogen concentration between about 1000 and 10,000 cubic feet per barrel of naphtha.

As a consequence of the discovery that heavy carbon deposits can not only be tolerated when employing a uidized hydroreforming catalyst, but are unexpectedly advantageous with respect to product distribution, our process can treat heavy naphtha charge stocks or a charge consisting of naphtha admixed with a minor amount of gas oil. Previously such charge stocks were thought to be objectionable for catalytic hydroreforming because of their tendency to lay down heavy carbon deposits on the catalyst. Thus, under the specific operating conditions and procedures of our process,'it is possible to avoid the Patented Jan. 1, 1957 expense of frequent removal of carbon from the catalyst and also to obtain a superior product by taking advantage of the heretofore unrecognized beneficial effect of carbon on the activity of a hydroreforming uidized catalyst.

The process of our invention is applicable for the upgrading of straight run naphthas or cracked naphthas. However, cracked stocks are preferably mixed with straight run stocks in mixtures in which the straight run stock predominates, The naphtha charge stock may range in composition from C5s to 565 C. end point material. In its ability to handle such high end point materials, our process differs markedly from previous catalytic reforming processes. Such processes have heretofore been limited to treatment of relatively light naphthas because heavy naphthas have caused excessive coke deposition and inactivation of the catalysts with the consequent requirement of frequent regeneration. Our process can tolerate very high carbon laydown on the catalyst and therefore can treat much heavier stocks than could the prior art catalytic reforming processes.

The charge to our process can consist essentially of a naphtha of the type described above. Within this definition would be included, for example, a mixture consisting of naphtha and less than one percent gas oil. Also, it can consist essentially of a predominant amount of naphtha and a minor amount, e. g., about l to 10 percent by weight, of a vaporizable heavier stock having inherently higher carbon-forming tendencies than the naphthas mentioned, such as a gas oil boiling substantially above the gasoline boiling range, for example from about 450 to 800 F. In other words, the charge is a hydrocarbon oil mixture selected from the group consisting of mixtures consisting essentially of naphtha and mixtures consisting essentially of a predominant amount of naphtha and a minor amount of gas oil. The gas oil can be a virgin or straight run gas oil but, because of the higher aromatic content of cycle stocks, it is preferably a'recycled gas oil fraction of the hydroreformed product or a catalytically or thermally Acracked recycle gas oil. The effect of adding the heavier stock to the naphtha charge is lto increase the rate at which carbon is initially formed on the fluidized catalyst and also to increase the equilibrium carbon level. For example, if with a certain -set of conditions and a particular naphtha charge, the carbon on the catalyst reaches an equilibrium level of about l5 percent by Weight, when about l0 percent of a catalytic cycle stock is mixed with the naphtha, the equilibrium carbon level might be increased to about i8 or 20 percent by weight. The result of the higher carbon level on the tluidized catalyst is to decrease dry gas production and improve the octane-yield relationship of the gasoline product.

The described charge stocks are treated in our hydroreforming process under special conditions with a conventional powdered iiuidized hydroreforming catalyst. The catalyst consists of a major amount of a carrier or base and a minor amount of a component which is a catalyst for reactions known variously as reforming, dehydrogenation, cyclization, aromatization, etc. For convenience, we will refer to these latter types of reactions as dehydrogenation reactions since all of them involve dehydrogenation. Thus, we will refer to our catalyst as having a carrier or base component, which may have cracking activity, and a dehydrogenation component. The dehydrogenation component preferably is selected from the group consisting of molybdenum, chromium, tungsten and the oxides of these metals. The carrier is a porous refractory material such as alumina, silica-activated alumina, silica-alumina composites, magnesium oxide, thorium oxide, acid-treated clays, or the like. A very desirable catalyst comprises 5 to 20 percent of molybdenum oxide supported on silica-activated alumina. The catalyst is employed in a finely divided or powdered form in order to permit duid catalyst operation. The catalyst particles range in size from about 60 to about 400 mesh, the bulk of the particles being in the range of from 200 to 400 mesh.

The process of the invention is carried out at temperatures between about 925 and 975 F. This elevated temperature is achieved and maintained during the endothermic reaction by heating the charge before its introduction to the reaction zone. The employment of a temperature within the mentioned range is very important for the successful operation of our process. Thus, at a temperature of below about 925 F. the carbonized catalyst is not sufficiently active for successful operation, and at temperatures above about 975 F. gasication of the charge is excessive, so that the high liquid yields of our process are not obtained.

The process is carried out in vapor phase under a pressure of at least about 200 pounds per square inch gauge. However, it is essential that the conditions of our process be such as would lay down carbon on the catalyst were the process to be started with a fresh catalyst. Also, our process should operate under hydrogen-producing rather than hydrogen-consuming conditions. For these reasons the pressure should not exceed about 1000 pounds per square inch gauge. The preferred range of pressure is between about 500 and 900 pounds per square inch gauge. it may also be explained at this point, that although our process is carried out within the carbon laydown region of pressure, i. e. below about 1000 pounds per square nh gauge, the amount of carbon for any particular ation appears to reach a certain maximum level or ,.iilibriurn and thereafter increases, if at all, only very slightly.

The process is carried out in the presence of a large quantity of hydrogen. While hydrogen from an exterior source may be used, it is more economical to recycle a hydrogen-rich gas separated from the reactor effluent. This gas consists predominantly of hydrogen from the dehydrogenation reactions and lesser amounts of light hydrocarbon gases produced by the minor amount of cracking which invariably takes place. The exact composition of the gas will vary with the particular feed treated. A sufficient amount of the hydrogen-rich gas is a cled so that at least 1000 cubic feet of hydrogen is recycled per barrel of feed. The preferred hydrogen co .entration is about 5000 cubic feet per barrel although larger amounts of hydrogen, up to about 10,000 cubic for per barrel of charge may be used. Then we recite specific values for hydrogen concentration in the specification and claims, we intend them to indicate the ratio of hydrogen to the total charge of hydrocarbon oil, whether the charge is naphtha or a mixture of naphtha and gas oil.

Under the specified conditions, a weight space velocity of about one to three weights of naphtha per weight of catalyst per hour will yield a particularly satisfactory product. However, hourly weight space velocities from about 0.5 up to about may often be advantageously employed.

Tn treating a feed stock as specified with the described catalyst under the specified conditions, the oei-stream period of the process can be very long. Thus, the process may be carried out continuously for periods as long as ral hundred hours without the necessity of subjecting the catalyst to a egeneration treatment. As mentioned 'l lsly. this long osi-stream period constitutes one of u ipal advantages of our process, since it greatly iccs te expense of regenerating catalyst which previou processes have incurred. When, after a long time, it becomes necessary to reactivate the catalyst, this may he done by any of the conventional regeneration treatmeats commonly used with reforming catalysts.

The deliberate deposition of carbon on the catalyst, which is an essential feature of our invention, may be brought about in any of several different ways. For

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example, the carbon may simply be deposited by a normal reforming operation with an initially clean catalyst. However, it is preferred that carbon be deposited by some procedure which will both deposit the carbon rapidly and produce an especially desirable product. Therefore, our preferred procedure is to deposit the carbon by an initial period of operation under very severe conditions which cause rapid deposition of carbon and yield a valuable highly aromatic product, 'for example, one very rich in naphthalene.

By severe conditions we mean, for example, a temperature higher than that at which we normally conduct our hydroreforming process and/ 0r a lower space velocity than in our normal operation so that the hydrocarbons are given a longer residence time in the reactor. Thus, under the severe conditions the temperature should be above about 975 F. if the other conditions are in the range for our normal hydroreforming procedure. In general, we prefer to use a low space velocity, e. g. below about 3.0 during the pretreatment stage and if the temperature is only about 975 F. or lower, the space velocity should be below about 0.5 to qualify as severe conditions. As an example of a set of conditions which are severe, we can cite a temperature of 1000 F., a pressure of 500 pounds per square inch gauge, hydrogen concentration of 2500 cubic feet per barrel of naphtha, and a space velocity of 0.5 weight of naphtha per weight of catalyst per hour. Under these conditions a straight run naphtha will deposit between about 10 and 25 percent carbon 0n the fluidized reforming catalyst within a period of about l to 5 hours.

Another preferred procedure is to cause rapid deposition of carbon on the catalyst during an initial stage of operation in which no fresh or recycled hydrogen is introduced to the reactor. This procedure has the advantages of causing rapid initial carbon deposition and yielding a valuable aromatic product. lt also has the advantage of decreasing the requirement of hydrogen storage facilities because no fresh hydrogen is required during the carbon-depositing, catalyst pretreatment period and, by the time the period of normal operation is reached, sufcient hydrogen for recycle is available in the product. When no hydrogen is charged it may be desirable to charge a uidizing gas to the reactor in case the hydrocarbon vapors alone cannot maintain the catalyst in the proper uidized condition. This tluidizing gas can be an inert gas such as nitrogen or llue gas. When the pretreatment is carried out in the absence of hydrogen it is not necessary that the temperature be very severe to deposit carbon. Generally, a temperature between about 850 and 1000 F. will be satisfactory for this purpose.

The hydrocarbon oil charge for the pretreatment period during which the carbon llaydown is deliberately encouraged may be the same naphtha or mixture of naphtha and gas oil which is subsequently charged to the normal hydroreforming stage. Also, it is possible to charge gas oil alone, or any desired mixture of gas oil and naphtha, during the pretreatment stage so as to rapidly deposit carbon. The gas oil should be vaporizable under the reaction conditions and can have a boiling range between about 450 and 800 F. One possible procedure is to charge gas oil alone during the pretreatment period unti the desired carbon laydown is obtained and then cut in naphtha until the charge comprises at least about percent naphtha for the normal hydroreforming period of the process. With the heavier charge consisting entirely or in part of gas oil, the carbon deposition will be fairly rapid even with our normal hydroreforming conditions or with temperatures as low as about 850 or 900 F. and the temperature need be no higher than about 10.70 F. However, the heavier charge may also be used when pretreatment is conducted under the very severe conditions referred to above or in the absence of hydrogen. In either of these Atwo latter instances the rate of carbon deposition will be somewhat more rapid if the heavier charge is used.

The process of our invention may be more readily understood by reference to the drawing which is a simplified ow diagram showing one form of apparatus suitable for use with our process. The reactor 1 may be referred to as a xed bed fluid catalyst reactor. That is to say, the reactor contains a bed of fluidized or suspended powdered catalyst which remains within the reactor throughout a reaction cycle. There is no continuous transfer of catalyst between the reactor anda regenerator as is usually the case in fluid catalyst processes. Feed gases are introduced into the bottom of reactor 1 by means of feed line 2. Heat for the endothermic reforming reaction is supplied by preheating the naphtha charge and the recycled or fresh hydrogen in heater 3, from which the mixed streams of hydrogen and vaporized naphtha pass upwardly via line 2, into the reactor 1, maintaining the powdered catalyst therein in a uidized condition. Product vapors are separated from catalyst fines by the cyclone separator 4, within the reactor. Product vapors pass overhead via line 5, passing through heat exchanger 6, and into absorber 7. A portion of light overhead gases from the absorber, principally hydrogen, is recycled to the process via line 8 and compressor 9, and a portion is vented through line 10. The absorber bottoms pass to product recovery equipment such as the fractionator 11 and the gasoline stabilizer 12. A portion of the fractionator bottoms is used as absorber oil, entering the absorber via line 13, and a portion is recycled to the reactor via line 14.

The process is normally hydrogen-producing so that suicient hydrogen is suppl-ied in the recycle gas to meet the hydrogen requirements. However, initially in the process it may be necessary to charge fresh hydrogen to the reactor. This hydrogen is passed into the hydrogen line 15 from the hydrogen storage tank 16 via line 17, and in line 2 mixes with the naphtha charge prior to entering the preheater.

In the modication of our process in which we use a catalyst pretreatment period during which no hydrogen is charged to the reactor, the valve 18 in the hydrogen line 8 will remain closed. The preheated vaporized naphtha is charged to the reactor 1 over a period of about one to tive hours at a temperature of about 925 to 975 F. During this period, a heavy deposit of carbon forms on the catalyst and a valuable highly aromatic product is recovered as bottoms from the stabilizer 12. When the carbon level on the catalyst has reached the desired point, say 20 percentby weight, valve 18 is opened and recycle gas is admitted to the reactor to provide a hydrogen concentration of between about 1000 and 10,000 cubic feet per barrel of naphtha. With this method of operation, the hydrogen storage tank 16 can be eliminated entirely or at least replaced by a smaller tank if some fresh hydrogen should be required.

A clear understanding of the manner in which our process is carried out can be obtained from the following description of one specific embodiment of our process. The process employed a typical powdered catalyst comprising 10 to 12 percent molybdenum tn'oxide on an alumina gel base stabilized with about 5 percent silicon dioxide. This catalyst had been used in previous reforming work but had been regenerated until free of carbon and then reduced with hydrogen. A West Texas straight run naphtha having a 50.0 A. P. I. gravity and a boiling range of 276 to 370 F. was passed through the uidized catalyst bed at 950 F. and atmospheric pressure at a weight space velocity of 1.0 weight of naphtha per weight of catalyst per hour for three hours. No recycle gas was used and fluidization was maintained by a stream of nitrogen. The liquid product obtained during this period was a very valuable aromatic material which, on being distilled, left a residue rich in naphthalene and naphthalene derivatives. At the end of the three hours, the catalyst 6 had deposited on it 21.6 percent carbon, 1.05 percent hydrogen, and 0.5 percent sulfur.

Following the above-described carbon lay-down period during which no hydrogen was passed into the reactor, the carbonized catalyst was employed for hydroreforrning a West Texas naphtha under our normal hydroreforming conditions. The treatment converted the naphtha to a high octane motor fuel with a very high liquid yield. Dry gas formation was exceptionally low. The operation was conducted for a period of more than 20 hours with no apparent decrease in catalyst activity.

The tables below record the operating conditions and results for the described hydroreforming process with the catalyst which had been pretreated to deposit carbon thereon. The results are recorded for two periods of the run, the first period extending `from the start of the operation to about l2 hours, and the second period extending from about 12 hours to the end of the onstream period, i. e., about 20 hours. The tables also show for comparison the operating conditions and results for hydroreforming a West Texas naphtha under conditions substantially the same as those for our process, with the exception that the catalyst did not receive the coke depositing pretreatment described above.

TABLE I Operating conditions recovery. With this table it is possible to compare the yields of our process with those of the process not employing a pretreated catalyst.

TABLE II Product recovery Process with Catalyst Pretreated Process with to Deposit Carbon Initially Carbon-Free Catalyst Period 1 Period 2 Recovery, Wt. Percent of Feed Sharged, Hydrocarbon Distribuion:

C; 4. 3 3. 0 6. 4 CL... 6.7 5.7 9.3 C3 8.8 7.9 14. 5 C4 7. 5 7. 4 13. 7 400 F. Gas ne (CH-) 64.3 69.7 55. 2 Residue 1. 4

Total 91.6 94. 6 100. 5

Recovery, Vol. Percent of Feed Charged:

4 18. 3 400 F. 55. S Residue 1.1

TOtal 75 3 79. 5 75 2 400 F. E. P. Gasoline (C3 free,

10 lbs. AVP 1) 73. 7 80.2 62. 3

1 AVP=Absolutc vapor pressure.

From the above table it can be seen that markedly higher yields of gasoline are obtained in both periods of our process than in the operation with the non-pretreated catalyst. This is true whether the percentage recovery is calculated on either a weight or volume basis. By either method of calculation it is quite clear that our TABLE HI Inspection data for charge stocks and products -uidized finely divided hydroreforming catalyst consisting essentially of from 5 to 20 percent by weight molybdenum oxide and a porous refractory carrier consisting essentially of alumina anda minor amount of silica, said catalyst having deposited thereon between about l and 25 percent by weight of carbon throughout said process, ata temperature between about 925 and 975 F, a pressure between about 200 and 1000 pounds per square inch gauge, Vat an hourly weight space velocity between about 0.5 and 5, and a hydrogen concentration of between about 1000 and 10,000 cubic feet per barrel of charge.

Product of Process Product of Feed to with Pretrcated Feed to Process Total Product (As Produced) Pretreated Catalyst N on-Prewith Non- Catalyst treated Pretreated Catalyst Catalyst .Period 1 Period 2 Gravity, A. P. I 50. 0 52. 1 52. 2 48. 6 55. 9 Distillation, F.:

LB. P 276 112 109 268 80 10% 295 150 160 304 119 50% 316 243 255 334 222 90%. 342 318 323 372 354 E. P-. 370 376 384 402 419 Total Arom 14.9 43. 2 40. 8 15. 2 43. 6 Bromlne l\'o 1. 0 4.1 5. 3 l 1. 9 l0.2 Sulfur, Percent (Lamp). 0. 256 0.012 0.000 l 0.271 l 0.012

Octane Numbers, Research:

Clear 37. 5 85. 5 82. 9 1 34. 0 I 00. 0 +3 ce. Tetraethyl lead 53. 8 96.1 94.2 1 51. 4 l 08. 7 Clear (Cs tree, lbs. 86. 3 84.1 1 90. 2

AVP). +3 ce. Tetraethyl lead 97. 1 95. 6 1 98. 8

(C: free, 10 lbs. AVP).

total product as produced.

Table lil when considered with the yield data of T able Il shows that for both the clear and leaded gasoline product of our process, the octane-yield relationships are superior to those of the process with the nonpretrcated catalyst.

Table HI .shows another benefit of our hydroreforming process which has not been mentioned before. This benefit is in removal of sulfur. The first column of Table IH shows that the feed to our process contained 0.256 percent by weight sulfur. ln the product of the first period of our process the sulfur content was reduced to 0.012 percent and in the product of the second period it was reduced to the negligible amount of 0.009 percent by weight. rhese excellent desulfurization results constitute an additional unobvious advantage of our process, inas- 'a much as it would normally not be expected that a treatment performed in the presence of such a heavily carbonized catalyst as we employ would desulfurize successfully.

Summarizing the results shown in the tables above, of this s ecic embodiment of our process, it can be said that our process affords an extremely high liquid yield of high octane, sulfur-free gasoline. The process achieves this result with extremely long on-stream periods without regeneration of the catalyst. ln the embodiment specically described, this on-stream period was more than hours.

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

l. The process for catalytically reforming in the prescnt-e of hydrogen a hydrocarbon oil mixture selected from the group consisting of mixtures consisting essentially of naphtha and mixtures consisting essentially of a predominant amount of naphtha and a minor amount of gas oil which comprises continuously contacting the hydrocarbon oil mixture 'with hydrogen in the presence of a 2. The process according to claim .1 in which said hydrocarbon oil mixture consists essentially of naphtha.

3. The process according to claim 1 in which said hydrocarbon oil mixture consists essentially of a predominant amount of naphtha and a minor amount of a gas oil.

4. The process which comprises, in a carbon-depositing, catalyst pretreatment period, contacting a carbonfree fiuidized finely divided reforming catalyst consisting essentially of from 5 to20percent by weight molybdenum oxide and a porous refractory carrier consisting essentially of .alumina and a minor amount of silica, with the vapors of a hydrocarbon oilselected from the group consisting of naphtha, gas oil, and mixtures thereof, at a temperature of between about 850 and 1000" F. at an hourly weight space velocity of less than about 3, at about atmospheric pressure and in the absence of hydrogen for a period of between about l and 5 hours, whereby there is deposited on said catalyst between about 10 and 25 percent by weight of carbon; thereafter, in a hydroreforming on-stream period of more than about 20 hours, continuously contacting the carbonized fluidized catalyst with afhydrocarbon oil consisting essentially of naphtha at a temperature between about 925 and E750 F., a pressure between about 200 and 1000 pounds per square inch gauge, at an hourly weight space velocity between about.0.5 and 5, and in the presence ofhydrogen in theamount of between about 1000 and 10,000 cubic feet per barrel of naphtha, said hydrogen being at least parof less than about 3, a pressure between about 200 and 1000 pounds per square inch gauge, in the presence of hydrogen in an amount of between about 1000 and 10,000 cubic feet per barrel of oil for a period of between about l and hours whereby there is deposited on said catalyst between about and 25 percent by weight of carbon; thereafter, in a hydroreforming on-stream period of more than about 20 hours, continuously contacting said carbonized luidized catalyst with a hydrocarbon oil consisting essentially of naphtha at a temperature between about 925 and 975 F., a pressure between about 200 and 1000 pounds per square inch gauge, at an hourly weight space velocity between about 0.5 and 5 and in the presence of hydrogen in the amount of between about 1000 and 10,000 cubic feet per barrel of naphtha, said hydrogen being at least partially obtained from the products of the pretreatment period and the on-stream period.

6. The process which comprises, in a carbondepositing, catalyst pretreatment period, contacting a tuidized nely divided reforming catalyst consisting essentially ot from 5 to 20 percent by weight molybdenum oxide and a porous refractory carrier consisting essentially of alumina and a minor amount of silica, with the vapors of a gas oil boiling in the range of about 450 to 800 F. at a temperature Ibetween about 850 and 1000" F., an hourly weight space velocity of less than about 3, and a pressure between about 200 and 1000 pounds per square inch, in the presence of hydrogen in the amount of between about 1000 and 10,000 cubic feet per barrel of oil for a period of between about l and 5 hours whereby there is deposited on said catalyst between about 10 and 25 percent by Weight of carbon; thereafter, in a hydroreforming on-stream period of more than about 20 hours, continuously contacting the carbonized tluidized catalyst with a hydrocarbon oil consisting essentially of naphtha at a temperature between about 925 and 975 F., a pressure between about 200 and 1000 pounds per square inch gauge, at an hourly weight space velocity between about 0.5 and 5, and in the presence of hydrogen in the amount of between about 1000 and 10,000 cubic feet per barrel of naphtha, said hydrogen being at least partially obtained from the products of the pretreatment period and the on-stream period.

`References Cited in the ile of this patent UNITED STATES PATENTS 1,967,636 Towne July 24, 1934 2,353,119 Workman July 4, 1944 2,481,824 Claussen et al Sept. 13, 1949 2,587,425v Adams et al. Feb. 26, 1952 OTHER REFERENCES Sachanen, Conversion of Petroleum, Reinhold Pub. Co., 1948, pages 206-211. 

1. THEPROCESS FOR CATALYTICALLY REFORMING IN THE PRESENCE OF HYDROGEN A HYDROCARBON OIL MIXTURE SELECTED FROM THE GROUP CONSISTING OF MIXTURES CONSISTING ESSENTIALLY OF NAPHTHA AND MIXTURES CONSISTING ESSENTIALLY OF A PREDOMINANT AMOUNT OF NAPHTHA AND A MINOR AMOUNT OF GAS OIL WHICH COMPRISES CONTINUOUSLY CONTACTING THE HYDROCARBON OIL MIXTURE WITH HYDROGEN IN THE PRESENCE OF A FLUIDIZED FINELY DIVIDED HYDROREFOPRMING CATALYST CONSISTING ESSENTIALLY OF FROM 5 TO 20 PERCENT BY WEIGHT MOLYBDENUM OXIDE AND A POROUS REFACTORY CARRIER CONSISTING ESSENTIALLY OF ALUMINA AND A MINOR AMOUNT OF SILICA, SAID CATALYST HAVING DEPOSITED THEREON BETWEEN ABOUT 10 AND 25 PERCENT BY WEIGHT OF CARBON THROUGHOUT SAID PROCESS, AT A TEMPERATURE BETWEEN ABOUT 925* AND 975* F., A PRESSURE BETWEEN ABOUT 200 AND 1000 POUNDS PER S QUARE INCH GUAGE, AT AN HOURLY WEIGHT SPACE VELOCITY BETWEEN ABOUT 0.5 AND 5, AND A HYDROGEN CONCENTRATION OF BETWEEN ABOUT 1000 AND 10,000 CUBIC FEET PER BARREL OF CHARGE. 